Abstract
Nor-adrenaline present in nerves cannot be the sympathin E of Cannon and Rosenblueth (1937). Sympathin E in its original meaning has never been prepared and its assumed properties have never been controlled. The actions attributed to sympathin E are due to the substance shown to be present in adrenergic nerves, having the properties of nor-adrenaline. Since there is no evidence for the presence of a sympathin E differing from nor-adrenaline, the former term should be dropped as inadequate.